Species

Pterostylis micromega

Etymology

Pterostylis: winged column

Common Name(s)

Swamp Greenhood

Current Conservation Status

2012 - Threatened - Nationally Endangered

Conservation status of New Zealand indigenous vascular plants, 2012
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2012 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2009 and replaces all previous NZTCS lists for vascular plants. Authors: Peter J. de Lange, Jeremy R. Rolfe, Paul D. Champion, Shannel P. Courtney, Peter B. Heenan, John W. Barkla, Ewen K. Cameron, David A. Norton and Rodney A. Hitchmough. File size: 792KB

Previous Conservation Status

Qualifiers

2012 - DP, EF
2009 - CD, DP, EF

Authority

Pterostylis micromega Hook.f.

Family

Orchidaceae

Flora Category

Vascular - Native

NVS Species Code

PTEMIC

The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.

Structural Class

Orchids

Synonyms

Distribution

Endemic. North, South and Chatham Islands. Once known from Kaitaia to Wellington, North Nelson and the Chatham Islands. The species is still present in the Huntly Basin, (Waikato), Volcanic Plateau, near Wanganui and in the Wairarapa. A plant was also known, until recently from Knuckle Hill, North West Nelson. That plant appears to have died out naturally. It was last reliably recorded from the Chatham Islands in the late 1800s.

Habitat

Coastal, lowland to subalpine (0 - 1000 m a.s.l.). A plant of bogs, fens and swamps, ranging from acidic to eutrophic. it often forms colonies of 5-30 plants, ranging from large-leaved non-flowering juveniles through to flowering adults. It can be found growing under willows (Salix spp.).

Similar Taxa

A distinctive greenhood of wetland habitats whose broad-elliptic leaves usually arranged in a loose rosette, and usually with finely undulating almost crisped margins, and rather large, erect, whitish flower with long tapering, arcuate dorsal sepal immediately separate this greenhood from the other New Zealand Pterostylis species.

Threats

Drainage of habitat; habitat invasion by weeds (in the Waikato royal fern (Osmunda regalis) seems to be the main weed threat); unrestricted wetland access by stock, and wild animals such as deer, pigs, and possums have proved to be a problem at some sites. Nevertheless this species requires some habitat disturbance to thrive, and soon succumbs if its habitat becomes to densely vegetated.

Chromosome No.

2n = 44

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

Where To Buy

Not commercially available.

Cultural Use/Importance

This is one of a number of orchids which have successfully colonised habitats now dominated by exotic species. For example in the Waikato several populations have been discovered thriving within the moss mounds developed under grey willow (Salix cinerea).

Attribution

Fact Sheet prepared from NZPCN by P.J. de Lange 1 October 2003. Description subsequently published in de Lange et al. (2007).